Response Characteristics of Cochlear Nucleus Neurons to Vowel Sounds

1977 ◽  
Vol 86 (1) ◽  
pp. 37-48 ◽  
Author(s):  
Allen L. Rupert ◽  
Donald M. Caspary ◽  
George Moushegian
Keyword(s):  
Cochlear Nucleus ◽  
Discharge Rate ◽  
Neuronal Responses ◽  
Response Characteristics ◽  
Cochlear Nuclei ◽  
Kangaroo Rat ◽  
Complete Basis ◽  
Pure Tones ◽  
Neural Discharge ◽  
Tonal Stimuli

Most studies in auditory neurophysiology have utilized tonal stimuli to determine the coding properties of neurons in the cochlear nuclei. In this investigation of the kangaroo rat, cochlear nuclei, neuronal responses to vowel sounds, as well as tones, were studied. The vowel sounds, each about 40 msec in duration were: [a], [i], [I], [ε], [o], [u], [Formula: see text] [æ], and [ṛ]. Five were linked together to form a 200 msec stimulus and various combinations of five vowel sounds provided us with 18 different stimuli. The results show that neurons in the cochlear nuclei are remarkably sensitive and selective to vowel sounds. Furthermore, the responses of these neurons to pure tones do not provide a complete basis to predict the types of responses to the vowel sounds. More significant is the finding that the neural discharge rate and pattern of discharge to a particular vowel may depend on where the vowel appears in the stimulus and what other vowel precedes it. This vowel positional effect is not the same for every neuron. We have called this phenomenon a neural “set.”

Fast Inhibition Alters First Spike Timing in Auditory Brainstem Neurons

2004 ◽  
Vol 92 (4) ◽  
pp. 2615-2621 ◽  
Author(s):  
Antonio G. Paolini ◽  
Janine C. Clarey ◽  
Karina Needham ◽  
Graeme M. Clark
Keyword(s):  
Lateral Inhibition ◽  
Cochlear Nucleus ◽  
Stellate Cell ◽  
Discharge Rate ◽  
Stellate Cells ◽  
Auditory Pathway ◽  
Auditory Brainstem ◽  
Spike Timing ◽  
Inhibitory Neurons

Within the first processing site of the central auditory pathway, inhibitory neurons (D stellate cells) broadly tuned to tonal frequency project on narrowly tuned, excitatory output neurons (T stellate cells). The latter is thought to provide a topographic representation of sound spectrum, whereas the former is thought to provide lateral inhibition that improves spectral contrast, particularly in noise. In response to pure tones, the overall discharge rate in T stellate cells is unlikely to be suppressed dramatically by D stellate cells because they respond primarily to stimulus onset and provide fast, short-duration inhibition. In vivo intracellular recordings from the ventral cochlear nucleus (VCN) showed that, when tones were presented above or below the characteristic frequency (CF) of a T stellate neuron, they were inhibited during depolarization. This resulted in a delay in the initial action potential produced by T stellate cells. This ability of fast inhibition to alter the first spike timing of a T stellate neuron was confirmed by electrically activating the D stellate cell pathway that arises in the contralateral cochlear nucleus. Delay was also induced when two tones were presented: one at CF and one outside the frequency response area of the T stellate neuron. These findings suggest that the traditional view of lateral inhibition within the VCN should incorporate delay as one of its principle outcomes.

Heterogeneous Neuronal Responses to Frequency-Modulated Tones in the Primary Auditory Cortex of Awake Cats

2008 ◽  
Vol 100 (3) ◽  
pp. 1622-1634 ◽  
Author(s):  
Ling Qin ◽  
JingYu Wang ◽  
Yu Sato
Keyword(s):  
Receptive Field ◽  
Auditory Cortex ◽  
Response Pattern ◽  
Primary Auditory Cortex ◽  
Neuronal Responses ◽  
Discrete Response ◽  
A Cell ◽  
Pure Tones ◽  
Awake Cats ◽  
Sweep Speed

Previous studies in anesthetized animals reported that the primary auditory cortex (A1) showed homogenous phasic responses to FM tones, namely a transient response to a particular instantaneous frequency when FM sweeps traversed a neuron's tone-evoked receptive field (TRF). Here, in awake cats, we report that A1 cells exhibit heterogeneous FM responses, consisting of three patterns. The first is continuous firing when a slow FM sweep traverses the receptive field of a cell with a sustained tonal response. The duration and amplitude of FM response decrease with increasing sweep speed. The second pattern is transient firing corresponding to the cell's phasic tonal response. This response could be evoked only by a fast FM sweep through the cell's TRF, suggesting a preference for fast FM. The third pattern was associated with the off response to pure tones and was composed of several discrete response peaks during slow FM stimulus. These peaks were not predictable from the cell's tonal response but reliably reflected the time when FM swept across specific frequencies. Our A1 samples often exhibited a complex response pattern, combining two or three of the basic patterns above, resulting in a heterogeneous response population. The diversity of FM responses suggests that A1 use multiple mechanisms to fully represent the whole range of FM parameters, including frequency extent, sweep speed, and direction.

Central compensation of vestibular deficits. IV. Responses of lateral vestibular neurons to neck rotation after labyrinth deafferentation

1985 ◽  
Vol 54 (4) ◽  
pp. 1006-1025 ◽  
Author(s):  
C. Xerri ◽  
S. Gianni ◽  
D. Manzoni ◽  
O. Pompeiano
Keyword(s):  
Conduction Velocity ◽  
Vestibular Nucleus ◽  
Discharge Rate ◽  
Acute Stage ◽  
Vestibular Neurectomy ◽  
Peak Displacement ◽  
Response Characteristics ◽  
Neck Rotation ◽  
The Mean ◽  
Decerebrate Cats

The response characteristics of neurons located in the lateral vestibular nucleus (LVN) to neck rotation at 0.026 Hz, 10 degrees peak displacement, have been investigated in precollicular decerebrate cats submitted to ipsilateral acute (aVN) or chronic vestibular neurectomy (cVN). On the whole, 105 units were tested after aVN (i.e., during the first postoperative hours) and 132 units after cVN (i.e., after full compensation of the postural and locomotor deficits). The neurons were histologically located either in the rostroventral (rvLVN) or the dorsocaudal part (dcLVN) of Deiters' nucleus, which are known to project mainly to the cervical and the lumbosacral cord, respectively. Moreover, 55 units in the former group and 66 units in the latter group were identified as vestibulospinal neurons projecting to lumbosacral segments of the spinal cord. The responses of these 237 LVN neurons to the neck input were then compared with those of 120 LVN neurons recorded previously in decerebrate cats with intact labyrinths. Whereas 58.3% of the LVN units recorded in control experiments were responsive to neck rotation, 69.5% of the units were affected by this stimulation at the acute stage of the neurectomy and 74.2% at the chronic stage. This increase in responsive units after aVN and cVN with respect to the controls was found exclusively in the dcLVN. The mean discharge rate of the responsive LVN neurons decreased from 40.7 +/- 48.9 (SD) imp/s in control experiments to 22.1 +/- 15.8 (SD) imp/s after a VN. Similar value was also obtained after cVN [25.0 +/- 17.2 (SD) imp/s], suggesting that compensation of the postural deficits elicited by the vestibular neurectomy results from a redistribution of the excitatory drive within different populations of LVN neurons. Indeed, the relation found in control experiments, i.e., that the faster the conduction velocity of vestibulospinal axons the lower was the unit discharge at rest, was lost after aVN, due to a decrease in resting discharge of the slow units. The mean discharge rate of the slow units, however, recovered after cVN, so that the negative correlation between resting discharge rate and axonal conduction velocity was reestablished. The average gain and sensitivity of the first harmonic response of the LVN neurons to neck rotation recorded after aVN and cVN were comparable to those obtained in preparations with the vestibular nerves intact.(ABSTRACT TRUNCATED AT 400 WORDS)

Discharge of spindle afferents from jaw-closing muscles during chewing in alert monkeys

1975 ◽  
Vol 38 (3) ◽  
pp. 560-571 ◽  
Author(s):  
G. M. Goodwin ◽  
E. S. Luschei
Keyword(s):  
Discharge Rate ◽  
Extracellular Recording ◽  
Muscle Spindles ◽  
Muscle Afferents ◽  
Upward Movement ◽  
Response Characteristics ◽  
Passive Response ◽  
The Face ◽  
Natural Foods ◽  
Discharge Patterns

The discharge of muscle spindle afferents from monkey spindle afferents from monkey jaw-closing muscles was studied during mastication of natural foods by extracellular recording from the fibers or cell bodies of the tract and mesencephalic nucleus of the fifth nerve. In all, 39 muscle afferents were studied. The spindle associated with 18 of the afferents was positively identified by the afferent's response to gentle, localized palpation of either the temporalis or masseter muscle. Discharge patterns were observed during mastication, and in the majority of cases the qualitative passive response characteristics of the spindle afferent were determined. During steady chewing spindle afferent discharge typically paused briefly during the initial rapid upward part of the chewing cycle. Firing generally began as the jaw slowed its upward movement, and firing rates during the slow grinding portion of the upward movement were within the range of 50-80 spikes/s. All spindles exhibited a brisk discharge during the opening movement, typically within the range of 100-150 spikes/s. One-third of the spindle afferents exhibited a brief, high-frequency burst of firing at the very beginning of the opening movement, presumably as a result of stretch applied to a spindle just previously subjects to fusimotor excitation. Although the results of the study make it clear that spindles in jaw-closing muscles are coactived along with the extrafusal muscle fibers, the fusimotor bias does not seem capable of sustaining discharge in the face of rapid shortening of the muscle. Furthermore, the fact that discharge rate during opening, when the jaw-closing motoneurons are quiescent, is much higher than at any part of the closing cycle, when the motoneurons are active, suggests that the muscle spindles cannot provide the primary excitatory drive to the motoneurons.

scholarly journals Response characteristics of pruriceptive and nociceptive trigeminoparabrachial tract neurons in the rat

2015 ◽  
Vol 113 (1) ◽  
pp. 58-70 ◽  
Author(s):  
Nico A. Jansen ◽  
Glenn J. Giesler
Keyword(s):  
Discharge Rate ◽  
Receptive Fields ◽  
Behavioral Responses ◽  
Spike Timing ◽  
Mustard Oil ◽  
Mechanical Stimuli ◽  
Firing Rates ◽  
Response Characteristics ◽  
Mapping Techniques ◽  
Thermal Stimuli

We tested the possibility that the trigeminoparabrachial tract (VcPbT), a projection thought to be importantly involved in nociception, might also contribute to sensation of itch. In anesthetized rats, 47 antidromically identified VcPbT neurons with receptive fields involving the cheek were characterized for their responses to graded mechanical and thermal stimuli and intradermal injections of pruritogens (serotonin, chloroquine, and β-alanine), partial pruritogens (histamine and capsaicin), and an algogen (mustard oil). All pruriceptive VcPbT neurons were responsive to mechanical stimuli, and more than half were additionally responsive to thermal stimuli. The majority of VcPbT neurons were activated by injections of serotonin, histamine, capsaicin, and/or mustard oil. A subset of neurons were inhibited by injection of chloroquine. The large majority of VcPbT neurons projected to the ipsilateral and/or contralateral external lateral parabrachial and Kölliker-Fuse nuclei, as evidenced by antidromic mapping techniques. Analyses of mean responses and spike-timing dynamics of VcPbT neurons suggested clear differences in firing rates between responses to noxious and pruritic stimuli. Comparisons between the present data and those previously obtained from trigeminothalamic tract (VcTT) neurons demonstrated several differences in responses to some pruritogens. For example, responses of VcPbT neurons to injection of serotonin often endured for nearly an hour and showed a delayed peak in discharge rate. In contrast, responses of VcTT neurons endured for roughly 20 min and no delayed peak of firing was noted. Thus the longer duration responses to 5-HT and the delay in peak firing of VcPbT neurons better matched behavioral responses to stimulation in awake rats than did those of VcTT neurons. The results indicate that VcPbT neurons may have important roles in the signaling of itch as well as pain.

Preferences for Single Tone Stimuli

1974 ◽  
Vol 22 (2) ◽  
pp. 136-142 ◽  
Author(s):  
Steven K. Hedden
Keyword(s):  
Analysis Of Variance ◽  
Factorial Analysis ◽  
Wave Form ◽  
Music Majors ◽  
Single Tone ◽  
Main Effect ◽  
Pure Tones ◽  
Nonmusic Majors ◽  
Tonal Stimuli ◽  
Frequency Intensity

This research used a factorial analysis of variance to examine preferences for tonal stimuli that differed in frequency, intensity, or wave form. For the sample of music majors, wave form appeared to have the greatest effect on preferences; pure tones were most preferred. The main effect for intensity also was significant, as was the interaction of intensity and wave form. For the sample of nonmusic majors, the predominant influence on preferences seemed to be intensity. The nonmusic majors preferred the softer of the two levels. In addition, the main effect for wave form was significant, as were the interactions of wave form with intensity and frequency with intensity.

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